> The largest users of h1b visas are firms that bring people to the US for a period of time to get trained, then have them return to their country of origin, offshoring the work

Minor detail, but if it's the same employer in both countries, they don't need to apply for H1, L1 would do the trick. It's also not subject to a cap and is much cheaper administratively.

So if companies are using H1 program for foreign employee training, that's a very inefficient practice.